{精度高边电流检测放大器的研究与设计*

作者：曲光阳，吴晓波 日期：2008-12-26/span> 浏览：3904 查看PDF文档

{精度高边电流检测放大器的研究与设计*

曲光阳，吴晓波
（浙江大学 超大规模集成电路研究所,浙江 杭州 310027）

摘要：为了给高效率电源管理类系统中的控制环路部分提供电流检测信号，提出了一种高精度高边电流检测放大器的设计。该放大器的输入级采用共基极接法，针对高低输入共模电平两种情况，采用两种模式切换工作的方式来适应宽输入共模电压。同时，对系统拓扑进行改善，提高系统的电压增益精度。放大器具有输入共模电压范围广且与电源电压无关，对电流检测放大精度高等特点。设计已在1.5 μm BCD工艺下实现。测试结果表明，在0 V～20 V的输入共模范围内，芯片都能正常检测高边电流，且当输入共模电压超出电源电压时，芯片也能正常工作，系统对电流测量的增益误差在-0.08％～0.26％之内，实现了预期的性能指标。
关键词：高边；电流检测放大器；共基极输入级；高精度
中图分类号：TN433文献标识码：A文章编号：1001-4551(2008)11-0001-04

Research and design of high accuracy highside current sense amplifier
QU Guangyang, WU Xiaobo
(Institute of Very Large Scale Integrated Circuit Design, Zhejiang University, Hangzhou 310027, China)
Abstract: To provide currentsense signals for the control loop in a high efficiency power management system, a high accuracy highside current sense amplifier was proposed. The amplifier uses a commonbase stage as the input stage, and two operation modes were adopted to fit the high and low input common mode voltage respectively, which guarantee its wide input common mode voltage range(ICMR)that is not limited by the supply voltage. Meanwhile, some improvement was proposed to enhance the gain accuracy of the system. The highside current sense amplifier features a wide ICMR independent of supply voltage and high gain accuracy of the currentsensing. The circuit was designed and fabricated in 1.5μm BCD technology. Test results showed that it works well over the input common mode range of 0~20 V, and the high side ICMR could be higher than the supply voltage. And the system current sensing gain error is within -0.08%~0.26%. All specifications are consistent with expectations well.
Key words: high side; current sense amplifier; common base input stage; high accuracy